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  1. Summary B factories and LHCb A. Bay LPHE EPF Lausanne

  2. CP & T violation only in K0 system ??? Since 1964, CP and or T violation was searched for in other systems than K0, other particles decays, EDM... No other signal until 2001... A. Bay LPHE EPF Lausanne

  3. BaBar (SLAC) and Belle (KEK) 8 GeV electrons 3.5GeV positron in 2001: observation of CP violation in the B meson system, using "asymmetric collider" B factories. KEKB machine:  production of (4s) (10.58GeV/c2)  = 0.425 (4s)  B0 B0  B+ B- A. Bay LPHE EPF Lausanne

  4. KEKB 24% Y(4s) 76% continuum year 2003: crossing the(psychological) luminosity barrier of 1034 cm-2s-1 1.5807 1034 on 18-May-2005 A. Bay LPHE EPF Lausanne

  5. Luminosity trend in the last 30 years Peak luminosity cm-2 s-1 A. Bay LPHE EPF Lausanne

  6. BaBar and Belle Study of the time dependent asymmetry in decay rates of B0 and anti-B0 CP violated  S ≠ 0 Dm = mass difference of "mass eigenstates" ~ 0.49 1012h/s A. Bay LPHE EPF Lausanne

  7. CP measurements at B factories Difficult: B0 mean life 1.54 10-12 s. Lorentz boost very small. B factories are asymmetric: the c.m. is moving. The two B decay at different position ~ on the z axis. We measure de difference Dz of the 2 vertices. Dr is small. Δz  cβγΔt ~ 200 m at Belle e (4s) n J/Y Ks D Dr Dz z1 z2 z A. Bay LPHE EPF Lausanne

  8. CP measurements at B factories (4s) J/Y Ks Dz z1 z2 z fCP region of B0 & B0 coherent evolution B0 and anti-B0 oscillate coherently (QMentangled state). When the first decays, the other is known to be of the opposite flavour  use the other side to infer the flavour, B0 or anti-B0, of the fCP parent e n D A. Bay LPHE EPF Lausanne

  9. Belle experiment Started in 1999 ~300 physicists from ~60 institutes in 14 countries. Aerogel Cherenkov n=1.015~1.030 SC solenoid 1.5T 3.5GeV e+ CsI(Tl) 16X0 E/E ~ 1.8% @1GeV TOF counter 8GeV e- Central Drift Chamber He/C2H5 (Pt/Pt)2=(0.0019 Pt)2+(0.0030)2 m / KL detection 14/15 layers of RPC+Fe  : efficiency > 90% <2% fake at p > 1GeV/c Particle ID : dE/dx in CDCdE/dx =6.9% TOFTOF = 95ps Aerogel Cerenkov ACC Efficiency = ~90%, Fake rate = ~6% 3.5GeV/c Si Vertex detector 3 layers  mid 2003 now 4 layers Impact parameter resolution  55m for p=1GeV/c A. Bay LPHE EPF Lausanne

  10. Belle ACC Silicon Vertex Detector SVD Impact parameter resolution  55m for p=1GeV/c at normal incidence Central Drift Chamber CDC (Pt/Pt)2 = (0.0019 Pt)2 + (0.0030)2 K/ separation : dE/dx in CDC dE/dx =6.9% TOFTOF = 95ps Aerogel Cerenkov ACC Efficiency = ~90%, Fake rate = ~6% 3.5GeV/c , e : CsI crystals ECL E/E ~ 1.8% @ E=1GeV e : efficiency > 90% ~0.3% fake for p > 1GeV/c KL and  : KLM (RPC)  : efficiency > 90% <2% fake at p > 1GeV/c 400 fb-1 4 108 B pairs ~ 8 m A. Bay LPHE EPF Lausanne

  11. Belle micro-vertex detector spatial resolution for Blepton + X sz (lepton) ~ 100 mm A. Bay LPHE EPF Lausanne

  12. Belle event A. Bay LPHE EPF Lausanne

  13. Particle ID in Belle dE/dx TOF Barrel ACC cut Endcap ACC p (GeV/c) Particle ID uses information from ACC, TOF, dE/dx( CDC) A. Bay LPHE EPF Lausanne

  14. Experimental program: measure sides and anglesof the CKM matrix a b quark t quark ~Vub g b ~Vtd decays ~Vcb oscillations CP asymmetries * CP violated in the SM => the area of triangle 0 * Any inconsistency could be a signal of the existence of phenomena not included in the SM Use B mesons phenomenology A. Bay LPHE EPF Lausanne

  15. Analysis and results a ~Vub ~Vtd g b ~Vcb • Continuum rejection • Kinematics at the Y(4s) • The Unitary triangle: • determination of Vub • " Vcb • " Vtd • " b • " a • " g • No time for other topics A. Bay LPHE EPF Lausanne

  16. Continuum rejection 24% Y(4s) 76% continuum Build Likelihood L for B and qq hypothesis using event shape variables and cos qB BB cut qq from event topology which is ~spherical for BB, jet like for continuum and angular distributions 0 0.2 0.4 0.6 0.8 1 A. Bay LPHE EPF Lausanne

  17. How to find a B meson?Kinematics variables at the Y(4S) GeV/c2 0.2 DE 0 -0.2 Mbc 5.2 5.24 5.28 GeV/c2 Gather candidates B and calculate (pB,EB). Boost to c.m. (pB*,EB*) with Example: B- D0p- "beam constrained mass" A. Bay LPHE EPF Lausanne

  18. Determination of Vcb B0 World Average: |Vcb| (inclusive) (42.0  0.6  0.8) 10-3 |Vcb| (exclusive) (40.2 +2.1) 10-3 -1.8 D0p+ Vcb W- q c b D*+ d g(y) known function of y F(y) hadronic form factor plus ~5% error on F(1) A. Bay LPHE EPF Lausanne (Moriond excl. D*: CLEO: 46.9 10-3 BABAR: 48.2 10-3)

  19. Determination of Vub Vub W b u hep-ex/0305037, with n reconstruction |Vub| (10-3) = 3.960.17(stat) 0.44(syst) 0.29(theo) 0.34(bc) 0.26(bu) bc bu Exemple: use lepton momentum distribution from inclusive semileptonic decays 0 1 2 3 Lepton momentum (in c.m.) GeV/c Less than 10% of the spectrum background free Average(inclusive) Vub=(4.12±0.13±0.60)10-3 A. Bay LPHE EPF Lausanne

  20. Determination of Vtd Vtd B0 Starting from a pure sample of B0, for instance, a B0component builds up in a time scale of a few ps: t b d B0 B0 W W t d b Probability 1 B0 measure oscillation frequency 0 3 6 9 ps A. Bay LPHE EPF Lausanne

  21. Dmd with di-lepton events * B0 and B0 oscillate coherently (QMentangled state). When the first decays, the other is known to be of the opposite flavour. * Tag B flavour from semileptonic B0 X-l+n B0 X+l-n region of B0 & B0 coherent evolution t ~ Dz/cbg * KEK-B boost  <Δz>  cβγt ~ 200 m e+ n (4s) m- X n Y Dz z z1 z2 A. Bay LPHE EPF Lausanne

  22. Dmd from di-lepton events .2 Missing mass N GeV2 -12 -8 -4 0 Background: B+ X0l+n B- X0l-n Selection strategy of the "soft pion tag" B0 D*-l+n Br3%  D0p- Br70% (Frederic Ronga, PhD thesis, 2003) • Event selection: • - 1st lepton P*> 1.8 GeV • 1 pion of opposite sign P* < 1 GeV • 2nd lepton P*> 1.3 GeV • - cut on Mn2 A. Bay LPHE EPF Lausanne

  23. Dmd from di-lepton events .3 SS OS -2 -1 0 1 2 -2 -1 0 1 2 Dz (mm) Dz (mm) Dz (mm) 0 1 2 Get Dz distributions for "Same Sign" and "Opposite Sign" leptons couples and fit for Dmd... OS SS J/  l+ l- to infer resolution A. Bay LPHE EPF Lausanne

  24. Dmd and Vtd average F. Ronga HEP-PH/0206171 B decay constant Bag parameter { ~20% error !  |Vtd | ~ (8±2)10-3 A. Bay LPHE EPF Lausanne

  25. UT sides Excluded area has <0.05 CL The Unitary Triangle inferred from its sides and from K0 data From K0 Dmd & Dms 0 1 Vub/Vcb A. Bay LPHE EPF Lausanne

  26. bfrom B0J/y Ks c J/y c Vcb b s B0 Ks d c b B0 d } SM: sin2b Golden Channel CKM phase = 0 J/y c Vcb Vtd Vtb d s CKM phase  0 ! B0 Ks Vtb Vtd Interference between the 2 amplitudes gives a "time-dependent CPV" A. Bay LPHE EPF Lausanne

  27. Any "direct" CP violation ? c J/y c Vcb b s B0 Ks d c b s } } SM: 0 sin2b CKM phase = 0 J/y t Vtb c Vts CKM phase = 0 B0 d Ks No "direct CPV" expected in SM in B J/y Ks, but who knows ?... A. Bay LPHE EPF Lausanne

  28. Time dependent asymmetry measurement Need to "tag" the flavour: B0 or B0. B0 and B0 oscillate coherently (QMentangled state)  use the other side to infer the flavour (4s) J/Y Ks Dz z1 z2 z e fCP n D region of B0 & B0 coherent evolution ftag t ~ Dz/cbg A. Bay LPHE EPF Lausanne

  29. b ccsreconstruction b ccs(J/KL excluded) B 0 J/KL 140 fb-1, 152MBB pairs 5417 events are used in the fit. pB GeV/c A. Bay LPHE EPF Lausanne

  30. A large CP asymmetry has been observed! World average (October 2005): SCP = 0.726 ± 0.037 ACP~ 0, compatible with no direct CPV SM: SCP = sin(2b) =>b =23.7° (or 66.3°) J/KL J/KL is OK A. Bay LPHE EPF Lausanne

  31. SM & KM model is verified ! b = 23.7°± 2.1° = 66.3°± 2.1° A. Bay LPHE EPF Lausanne

  32. UT with sin2b The Unitary Triangle fit including sides, K0 data, and sin2b A. Bay LPHE EPF Lausanne

  33. b sss, a B0f Ks puzzle ? s s B0 B0 d d d d b to s transition is second order (gluonic penguin). Prediction from SM: ~ same value of sin(2b) as in ccs because no additional phase from the loop. s Vts W Vtb* f b t s Ks s ??? ??? f c b unless new physics enters the loop. For instance: squark s A. Bay LPHE EPF Lausanne

  34. B0f Ks .2 sin2b(ccs) 5.2 5.4 5.28 GeV/c2 B0 fKS 6811 signals 106 candidates in the fit purity = 0.640.10 efficiency = 27.3% Beam-Energy Constrained Mass BaBar A. Bay LPHE EPF Lausanne

  35. gfrom BD0K D0 Ksp+p- Ks u K+ u p+ D0 s s p- Ks b b B+ p+ c c K+ B+ u D0 u p- D0 and D0 decay to same final state  mixed state is produced: See A.Giri, Yu.Grossman, A.Soffer, J.Zupan hep-ph/0303187 a, d, g unknown Dalitz's analysis with variables and A. Bay LPHE EPF Lausanne

  36. gfrom BD0K D0 Ks p+p- .2 3 2 1 0.5 1 1.5 2 2.5 3 D0Ksp+p- as a sum of 2 body decays a = 0.33±0.10±0.03±0.03 d = 162° +20-25 ±12°±24° g = 95° +25-20 ±13°±10° Fit Dalitz plot with a, d, g as free parameters 90%CL: 61°< g < 142° preliminary A. Bay LPHE EPF Lausanne

  37. Belle: very, very preliminary A. Bay LPHE EPF Lausanne

  38. afromB0pp d p - u W W d - p t g Consider B0p+p- first: without penguin contributions: App= 0 Spp= sin(2b+2g)= -sin(2a) This is not the case: large "penguin pollution" expected (but intrinsically interesting..!) Isospin analysis needed for the extraction of a. Need to measure alsoB0p0p0, B+p+p0,... A. Bay LPHE EPF Lausanne

  39. B0p+p- App0 continuum p+p- Kp syst. primarily from background fraction charmless 3-body B decay Phys Rev from ~231 p+p- : App= +0.58 0.15 0.07 Spp= -1.00 ± 0.21 ± 0.07 BABAR: App = 0.30 ± 0.25 ± 0.04 Spp = 0.02 ± 0.34 ± 0.05 hep-ex/0401029 A. Bay LPHE EPF Lausanne

  40. B0p+p-.2 Belle BaBar direct CVP A. Bay LPHE EPF Lausanne

  41. First signal from B0p0p0 B+r+p0 p+p0 Mbc [GeV/c2] continuum using 152 M BB: Br(B0p0p0) = (1.7 ± 0.6 ± 0.2)10-6 Phys. Rev. Lett. 91 (2003) 261801 BABAR: Br(B0p0p0) = (2.1 ± 0.6 ± 0.3)10-6 (hep-ph/0306058 gives 74° < a < 132°... ) A. Bay LPHE EPF Lausanne

  42. Global fit of data from all sources A. Bay LPHE EPF Lausanne

  43. Test of SM in quark sector:check the triangle ! Does SM give a coherent picture of CP violation ? Unitary triangle can be build using its sides or the angles. Other information comes form CPV with Kaons and B. All the information must be consistent (else  new physics ? or measurement error ? or bad supporting theory ?) A. Bay LPHE EPF Lausanne

  44. Test of SM in quark sector sin(2) = 0.687 ± 0.032 from J/K0 sin(2) = 0.793 ± 0.033 from sides sin(2) = 0.726 ± 0.037 from J/K0 sin(2) = 0.734 ± 0.043 from sides 2.3 from sides Summer 2005 Summer 2004 2005 test not so good... Compare unitarity triangle from CP-violating processes K CPV in K sector and sin(2) CPV in B sector with unitarity triangle measured from the sides only i.e.from CP-conserving processes (|Vub| and md, ms) (68% and 95% CL contours) A. Bay LPHE EPF Lausanne

  45. Test of SM in quark sector .2 Measure unitarity triangle only from the angles in B decays: sin(2) from B0  (cc)K0 interference of bc amplitude with B0_B0 mixing  (or +) from B  , ,  interference of bu amplitude with B0 _B0 mixing  from B  D(*)K interference of bc and bu amplitudes Compare again with trianglefrom (CP conserving) side measurements Test passed. A. Bay LPHE EPF Lausanne

  46. sin(2) from bs penguin Naive average of all bs modesdeviated from B(cc)K0 modesby 3.8 in 2003, now only 2.6  sin(2)eff=0.43±0.07 to be compared with all charmonium result 0.726±0.036 A. Bay LPHE EPF Lausanne

  47. Other topics (a few hep-ex) CPV results: • sin(2b) from J/y p0 hep-ex/0308053 • g from BD* p hep-ex/0308048 Rare B decays: • B hh {pp, Kp, KK, rp, rr} hep-ex/0307077,hep-ex/0306007 • BKhh {Kpp, KKK, KKp} hep-ex/0307082 • B pph, pLp hep-ex/0302024 • BK(*)g, fK(*)g, K(*)ll hep-ex/0308044 • B ffK hep-ex/0305068 • B LcpPhys. Rev . Lett. 90 (2003) 121802 EPR & Bell test of QM: hep-ex/0310192 New charmonium X(3871): Phys. Rev. Lett. 91 (2003) 262001 A. Bay LPHE EPF Lausanne

  48. CKM matrix 2007 • CDF + D0: 4 fb-1 each • BABAR + Belle: ~1000 fb-1 • CLEO-C • * s(sin(2b)) ≈ 0.03 from B0 J/ KS * no precise measurement of other angles * s(|Vij|)/|Vij| ~ down strange beauty up 0.1% 1% 5% charm 2% 2% 3% top 5% 5% 29% A. Bay LPHE EPF Lausanne

  49. Picture will be already inconsistent ? CKM triangle in 2007 (SM) from Dm b from B J/y Ks from bu from bc A. Bay LPHE EPF Lausanne

  50. BEYOND 2007 A. Bay LPHE EPF Lausanne